手机外壳的注塑模具设计与加工开题报告

编号无锡太湖学院毕业设计（论文）相关资料题目：手机外壳的注塑模具设计与加工 信机 系 机械工程及其自动化 专业2013年5月25日目 录一、毕业设计（论文）开题报告二、毕业设计（论文）外文资料翻译及原文三、学生“毕业论文（论文）计划、进度、检查及落实表”四、实习鉴定表无锡太湖学院毕业设计（论文）开题报告题目：手机外壳的注塑模具设计与加工 信机系 机械工程及其自动化 专业学 号： 0923275 学生姓名： 陈 兵 指导教师： 王士同 （职称：教 授 ） （职称： ）2012年11月12日课题来源某模具公司提供，该产品为手机背面外壳，要求设计一套模具来生产它，预估产量比较大，所以设计为一模两腔。科学依据（包括课题的科学意义；国内外研究概况、水平和发展趋势；应用前景等）（1）课题科学意义众所周知中国很早就开始制作模具和使用模具，但长期未形成产业。不过从上个世纪80年代开始，在国家产业政策和与之配套的一系列国家经济政策的支持和引导下，我国模具工业发展迅速，年均增速均为21%，至2005年我国模具总产值约为610亿元，其中塑料模具约30%左右。在未来的模具市场中，塑料模在模具总量中的比例还将逐步提高。模具技术的进步极大地促进了工业产品的生产发展，模具是“效益放大器”，用模具生产最终产品的价值将超过自身价格的几十倍乃至百倍及上千倍。据各国报导，模具工业在欧美等工业发达国家被称之“点铁成金”的“磁力工业”，虽然我国模具行业已经驶入发展快车道，但由于在精度、寿命、制造周期及能力等方面，与国际水平和工业先进国家相比尚有较大差距，所以还不能满足我国制造业发展的需求。特别是在精密、大型、复杂、长寿命模具方面，中国与国际平均水平和发达国家仍有较大差距，因此，每年尚需大量进口。 不过当前全球制造业转移的规模不断加大，中国已成为世界上最大的制造业之地，并正向深度和广度延伸，而我国的模具制造业正是承接转移的较为理想之地。目前国家正在大力支持具工业的发展，在多重有利条件下，我国模具行业的未来将展现出一派美好景色。研究内容 调查、研究、查阅文献和搜集资料； 阅读和翻译与研究内容有关的外文资料； 撰写开题报告 掌握CAD,UG等模具设计方面的软件； 详细设计内容（浇注系统，冷却系统，顶出系统，机构系统等）或研究方法 ； 设计或有关计算； 撰写毕业设计（论文）。拟采取的研究方法、技术路线、实验方案及可行性分析（1）实验方案模具课题的研究很难用准确的数学模型来描述。他很大一部分靠设计人员的经验。所以我们从传统的将其分为四部分。1 设计前准备工作：明确设计的要求以及必要的设计资料，研究材料的工艺成型性。2方案设计：确定模具结构包括结构类型，型腔数目，分型面，浇注系统，排气方式，冷却系统等3零部件的设计：排气结构设计，成型零件设计，温度调控系统设计，模架选择，顶出机构设计，模具材料选择等4后期阶段：绘制零件图以及总装配图，使用说明书。（2）研究方法本课题的主要通过AUTOCAD，UG等软件的辅助设计将模具各个零件绘制出来以构成各个系统与结构，在通过对结构的分析修改以达到可以加工产品要求。 研究计划及预期成果研究计划：2012年12月12日-2012年12月25日：按照任务书要求查阅论文相关参考资料，填写毕业设计开题报告书。2013年1月11日-2013年3月5日：填写毕业实习报告。2013年3月8日-2013年3月14日：按照要求修改毕业设计开题报告。2013年3月15日-2013年3月21日：学习并翻译一篇与毕业设计相关的英文材料。2013年3月22日-2013年4月11日：模具分模以及模具结构设计。2013年4月12日-2013年4月25日：模具相关2D图面绘制。2013年4月26日-2013年5月21日： 毕业论文撰写和修改工作。预期成果：利用设计出来的模具将产品生产出来，并达到预期效果特色或创新之处 可以代替机床将产品生产出来，并实现自动化。 实现了对产品的大批量复制性生产。已具备的条件和尚需解决的问题 提高了生产效率。 该模具结构还需要改善，精度还有待提高。指导教师意见 指导教师签名：年 月 日教研室（学科组、研究所）意见 教研室主任签名： 年 月 日系意见 主管领导签名： 年 月 日英文原文Automated surface finishing of plastic injection mold steel with spherical grinding and ball burnishing processesAbstractThis study investigates the possibilities of automated spherical grinding and ball burnishing surface finishing processes in a freeform surface plastic injection mold steel PDS5 on a CNC machining center. The design and manufacture of a grinding tool holder has been accomplished in this study. The optimal surface grinding parameters were determined using Taguchis orthogonal array method for plastic injection molding steel PDS5 on a machining center. The optimal surface grinding parameters for the plastic injection mold steel PDS5 were the combination of an abrasive material of PA Al2O3, a grinding speed of 18 000 rpm, a grinding depth of 20 m, and a feed of 50 mm/min. The surface roughness Ra of the specimen can be improved from about 1.60 m to 0.35 m by using the optimal parameters for surface grinding. Surface roughness Ra can be further improved from about 0.343 m to 0.06 m by using the ball burnishing process with the optimal burnishing parameters. Applying the optimal surface grinding and burnishing parameters sequentially to a fine-milled freeform surface mold insert, the surface roughness Ra of freeform surface region on the tested part can be improved from about 2.15 m to 0.07 m.Keywords Automated surface finishing Ball burnishing process Grinding process Surface roughness Taguchis method1 IntroductionPlastics are important engineering materials due to their specific characteristics, such as corrosion resistance, resistance to chemicals, low density, and ease of manufacture, and have increasingly replaced metallic components in industrial applications. Injection molding is one of the important forming processes for plastic products. The surface finish quality of the plastic injection mold is an essential requirement due to its direct effects on the appearance of the plastic product. Finishing processes such as grinding, polishing and lapping are commonly used to improve the surface finish.The mounted grinding tools (wheels) have been widely used in conventional mold and die finishing industries. The geometric model of mounted grinding tools for automated surface finishing processes was introduced in. A finishing process mode of spherical grinding tools for automated surface finishing systems was developed in. Grinding speed, depth of cut, feed rate, and wheel properties such as abrasive material and abrasive grain size, are the dominant parameters for the spherical grinding process, as shown in Fig. 1. The optimal spherical grinding parameters for the injection mold steel have not yet been investigated based in the literature.Fig.1. Schematic diagram of the spherical grinding processIn recent years, some research has been carried out in determining the optimal parameters of the ball burnishing process (Fig. 2). For instance, it has been found that plastic deformation on the workpiece surface can be reduced by using a tungsten carbide ball or a roller, thus improving the surface roughness, surface hardness, and fatigue resistance. The burnishing process is accomplished by machining centers and lathes. The main burnishing parameters having significant effects on the surface roughness are ball or roller material, burnishing force, feed rate, burnishing speed, lubrication, and number of burnishing passes, among others. The optimal surface burnishing parameters for the plastic injection mold steel PDS5 were a combination of grease lubricant, the tungsten carbide ball, a burnishing speed of 200 mm/min, a burnishing force of 300 N, and a feed of 40 m. The depth of penetration of the burnished surface using the optimal ball burnishing parameters was about 2.5 microns. The improvement of the surface roughness through burnishing process generally ranged between 40% and 90%.Fig. 2. Schematic diagram of the ball-burnishing processThe aim of this study was to develop spherical grinding and ball burnishing surface finish processes of a freeform surface plastic injection mold on a machining center. The flowchart of automated surface finish using spherical grinding and ball burnishing processes is shown in Fig. 3. We began by designing and manufacturing the spherical grinding tool and its alignment device for use on a machining center. The optimal surface spherical grinding parameters were determined by utilizing a Taguchis orthogonal array method. Four factors and three corresponding levels were then chosen for the Taguchis L18 matrix experiment. The optimal mounted spherical grinding parameters for surface grinding were then applied to the surface finish of a freeform surface carrier. To improve the surface roughness, the ground surface was further burnished, using the optimal ball burnishing parameters.Fig. 3. Flow chart of automated surface finish using spherical grinding and ball burnishing processes2 Design of the spherical grinding tool and its alignment deviceTo carry out the possible spherical grinding process of a freeform surface, the center of the ball grinder should coincide with the z-axis of the machining center. The mounted spherical grinding tool and its adjustment device was designed, as shown in Fig. 4. The electric grinder was mounted in a tool holder with two adjustable pivot screws. The center of the grinder ball was well aligned with the help of the conic groove of the alignment components. Having aligned the grinder ball, two adjustable pivot screws were tightened; after which, the alignment components could be removed. The deviation between the center coordinates of the ball grinder and that of the shank was about 5 m, which was measured by a CNC coordinate measuring machine. The force induced by the vibration of the machine bed is absorbed by a helical spring. The manufactured spherical grinding tool and ball-burnishing tool were mounted, as shown in Fig. 5. The spindle was locked for both the spherical grinding process and the ball burnishing process by a spindle-locking mechanism.Fig.4. Schematic illustration of the spherical grinding tool and its adjustment deviceFig.5. (a) Photo of the spherical grinding tool (b) Photo of the ball burnishing tool3 Planning of the matrix experiment3.1 Configuration of Taguchis orthogonal arrayThe effects of several parameters can be determined efficiently by conducting matrix experiments using Taguchis orthogonal array. To match the aforementioned spherical grinding parameters, the abrasive material of the grinder ball (with the diameter of 10 mm), the feed rate, the depth of grinding, and the revolution of the electric grinder were selected as the four experimental factors (parameters) and designated as factor A to D (see Table 1) in this research. Three levels (settings) for each factor were configured to cover the range of interest, and were identified by the digits 1, 2, and 3. Three types of abrasive materials, namely silicon carbide (SiC), white aluminum oxide (Al2O3, WA), and pink aluminum oxide (Al2O3, PA), were selected and studied. Three numerical values of each factor were determined based on the pre-study results. The L18 orthogonal array was selected to conduct the matrix experiment for four 3-level factors of the spherical grinding process.Table1. The experimental factors and their levels3.2 Definition of the data analysisEngineering design problems can be divided into smaller-the better types, nominal-the-best types, larger-the-better types, signed-target types, among others 8. The signal-to-noise (S/N) ratio is used as the objective function for optimizing a product or process design. The surface roughness value of the ground surface via an adequate combination of grinding parameters should be smaller than that of the original surface. Consequently, the spherical grinding process is an example of a smaller-the-better type problem. The S/N ratio, , is defined by the following equation: =10 log10(mean square quality characteristic) =10 log10where:yi : observations of the quality characteristic under different noise conditions n: number of experimentAfter the S/N ratio from the experimental data of each L18 orthogonal array is calculated, the main effect of each factor was determined by using an analysis of variance (ANOVA) technique and an F-ratio test. The optimization strategy of the smaller-the better problem is to maximize , as defined by Eq. 1. Levels that maximize will be selected for the factors that have a significant effect on . The optimal conditions for spherical grinding can then be determined.4 Experimental work and resultsThe material used in this study was PDS5 tool steel (equivalent to AISI P20), which is commonly used for the molds of large plastic injection products in the field of automobile components and domestic appliances. The hardness of this material is about HRC33 (HS46). One specific advantage of this material is that after machining, the mold can be directly used for further finishing processes without heat treatment due to its special pre-treatment. The specimens were designed and manufactured so that they could be mounted on a dynamometer to measure the reaction force. The PDS5 specimen was roughly machined and then mounted on the dynamometer to carry out the fine milling on a three-axis machining center made by Yang-Iron Company (type MV-3A), equipped with a FUNUC Company NC-controller (type 0M). The pre-machined surface roughness was measured, using Hommelwerke T4000 equipment, to be about 1.6 m. Figure 6 shows the experimental set-up of the spherical grinding process. A MP10 touch-trigger probe made by the Renishaw Company was also integrated with the machining center tool magazine to measure and determine the coordinated origin of the specimen to be ground. The NC codes needed for the ball-burnishing path were generated by PowerMILL CAM software. These codes can be transmitted to the CNC controller of the machining center via RS232 serial interface.Fig.6. Experimental set-up to determine the optimal spherical grinding parametersTable 2 summarizes the measured ground surface roughness alue Ra and the calculated S/N ratio of each L18 orthogonal array sing Eq. 1, after having executed the 18 matrix experiments. The average S/N ratio for each level of the four actors is shown graphically in Fig. 7.Table2. Ground surface roughness of PDS5 specimenExp.Inner array (control factors)Measured surface roughness value (Ra)ResponsenoABCDS/N(dB)Mean111110.350.350.359.1190.350212220.370.360.388.6340.370313330.410.440.407.5970.417421230.630.650.643.8760.640522310.730.770.782.3800.760623120.450.420.397.5300.420731320.340.310.329.8010.323832130.270.250.2811.4710.267933210.320.320.329.8970.3201011220.350.390.408.3900.3801112330.410.500.436.9680.4471213110.400.390.427.8830.4031321130.330.340.319.7120.3271422210.480.500.476.3120.4831523320.570.610.534.8680.5701631310.590.550.545.0300.5601732120.360.360.358.9540.3571833230.570.530.535.2930.543Fig.7. Plots of control factor effectsThe goal in the spherical grinding process is to minimize the surface roughness value of the ground specimen by determining the optimal level of each factor. Since log is a monotone decreasing function, we should maximize the S/N ratio. Consequently, we can determine the optimal level for each factor as being the level that has the highest value of . Therefore, based on the matrix experiment, the optimal abrasive material was pink aluminum oxide; the optimal feed was 50 mm/min; the optimal depth of grinding was 20 m; and the optimal revolution was 18 000 rpm, as shown in Table 3.The optimal parameters for surface spherical grinding obtained from the Taguchis matrix experiments were applied to the surface finish of the freeform surface mold insert to evaluate the surface roughness improvement. A perfume bottle was selected as the tested carrier. The CNC machining of the mold insert for the tested object was simulated with Power MILL CAM software. After fine milling, the mold insert was further ground with the optimal spherical grinding parameters obtained from the Taguchis matrix experiment. Shortly afterwards, the ground surface was burnished with the optimal ball burnishing parameters to further improve the surface roughness of the tested object (see Fig. 8). The surface roughness of the mold insert was measured with Hommelwerke T4000 equipment. The average surface roughness value Ra on a fine-milled surface of the mold insert was 2.15 m on average; that on the ground surface was 0.45 m on average; and that on burnished surface was 0.07 m on average. The surface roughness improvement of the tested object on ground surface was about (2.150.45)/2.15 = 79.1%, and that on the burnished surface was about (2.150.07)/2.15 = 96.7%.Fig.8. Fine-milled, ground and burnished mold insert of a perfume bottle5 ConclusionIn this work, the optimal parameters of automated spherical grinding and ball-burnishing surface finishing processes in a freeform surface plastic injection mold were developed successfully on a machining center. The mounted spherical grinding tool (and its alignment components) was designed and manufactured. The optimal spherical grinding parameters for surface grinding were determined by conducting a Taguchi L18 matrix experiments. The optimal spherical grinding parameters for the plastic injection mold steel PDS5 were the combination of the abrasive material of pink aluminum oxide (Al2O3, PA), a feed of 50 mm/min, a depth of grinding 20 m, and a revolution of 18 000 rpm. The surface roughness Ra of the specimen can be improved from about 1.6 m to 0.35 m by using the optimal spherical grinding conditions for surface grinding. By applying the optimal surface grinding and burnishing parameters to the surface finish of the freeform surface mold insert, the surface roughness improvements were measured to be ground surface was about 79.1% in terms of ground surfaces, and about 96.7% in terms of burnished surfaces. 中文译文基于注塑模具钢研磨和抛光工序的自动化表面处理摘要这篇文章研究了注塑模具钢自动研磨与球面抛光加工工序的可能性，它可以在数控加工中心完成注塑模具钢PDS5的塑性曲面。这项研究已经完成了磨削刀架的设计与制造。 最佳表面研磨参数是在钢铁PDS5 的加工中心测定的。对于PDS5注塑模具钢的最佳球面研磨参数是以下一系列的组合：研磨材料的磨料为粉红氧化铝，进给量50毫米/分钟，磨削深度20微米，磨削转速为18000RPM。表面粗糙度Ra值可由大约1.60微米改善至0.35微米，通过用优化的参数进行表面研磨。 如果用球抛光工艺和参数优化抛光，还可以进一步改善表面粗糙度Ra值，一般从0.343微米至0.06微米左右。而在模具内部曲面的测试部分，用最佳参数的表面研磨、抛光，曲面表面粗糙度就可以提高约2.15微米至0.07微米。关键词: 自动化表面处理 抛光 磨削过程 表面粗糙度 田口方法 一、引言步距研磨高度球磨研磨进给速度工作台由于塑胶工程材料的重要特点,比如耐化学腐蚀性、低密度、易于制造,并且已经日渐取代了金属部件在工业中广泛应用。 在注塑成型领域，其对于塑料制品是一个重要工艺。设计的本质要求是注塑模具的表面质量,因为它直接影响了塑胶产品的外观和性能。 加工工艺如球面研磨、抛光常用于改善表面光洁度。图1 球面研磨过程示意图研磨工具(轮子) 的安装的磨削工具（车轮）已被广泛地用在常规的模具和模具精加工产业。安装的几何模型的整理工序引入英寸甲球面磨削工具自动化表面精加工处理模式的状态下，完成系统开发英寸磨削速度，切削深度，进给速率，如研磨材料和车轮属性自动化表面的磨削工具。和磨料颗粒的大小，是用于球形研磨过程的主要参数，如在图所示。1。的最佳的球形研磨参数用于注射模具钢中尚未调查是根据在文献中。在最近几年中，已经进行了一些研究，在确定球抛光过程（图2）的最优参数。比如，已发现，可以减少使用的钨硬质合金球或辊在工件表面上的塑性变形，从而改善表面粗糙度，表面硬度和耐疲劳性。抛光过程是通过加工中心和车床。主要的抛光参数，具有显着的表面粗糙度的影响的滚珠或滚子材料，抛光力，进给速率，抛光速度快，润滑和抛光通行证的数量，等等。最佳的表面的塑料